A 10-year-old dog with blue-gray opacity in both lenses, normal menace, and normal pupillary responses; retroillumination shows no true opacity. What is the most likely diagnosis?

A 10-year-old dog with blue-gray opacity in both lenses, normal menace, and normal pupillary responses; retroillumination shows no true opacity. What is the most likely diagnosis?

• A. Nuclear sclerosis
• B. Cataract
• C. Retinal detachment
• D. Glaucoma

Answer: (A)

In dogs, a bilateral blue-gray haze across the lenses in an older animal with preserved vision points to nuclear sclerosis. This age-related lens change thickens and hardens the lens nucleus, scattering light to create that bluish appearance without forming a true, dense cataract. Because vision remains intact—reflected by normal menace responses and normal pupil reactions—the lens changes are not severe enough to impair sight. Retroillumination helps differentiate this from a cataract: a true cataract would produce a definite opacity on retroillumination, whereas nuclear sclerosis gives a subtle blue haze without a discrete opacity. In contrast, retinal detachment or glaucoma would more likely affect vision or pupillary responses and wouldn’t present as a symmetrical blue-gray lens haze with normal reflexes.

In dogs, a bilateral blue-gray haze across the lenses in an older animal with preserved vision points to nuclear sclerosis. This age-related lens change thickens and hardens the lens nucleus, scattering light to create that bluish appearance without forming a true, dense cataract. Because vision remains intact—reflected by normal menace responses and normal pupil reactions—the lens changes are not severe enough to impair sight. Retroillumination helps differentiate this from a cataract: a true cataract would produce a definite opacity on retroillumination, whereas nuclear sclerosis gives a subtle blue haze without a discrete opacity. In contrast, retinal detachment or glaucoma would more likely affect vision or pupillary responses and wouldn’t present as a symmetrical blue-gray lens haze with normal reflexes.